How does the poet use metaphor in the poem, The Thought-Fox?

The poet uses an extended metaphor, to describe his internal world as a dark landscape during winter. There is a forest contained within a single “midnight moment” (Line 1) — most likely a coniferous (or evergreen) forest, as the eventual light reveals a “deepening greenness” (Line 18) despite the heavy snow. The snow itself represents the speaker’s blank page, as well as the vast limitlessness of artistic potential. The winter setting suggests a feeling of emptiness and barrenness and stunted growth, while the hints of plant matter and the energy of the fox gives the setting a feeling of hope and renewal.